JP2015034099A - Hydrogen generator and hydrogen generation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen generator which can safely and efficiently generate hydrogen by a simple configuration.SOLUTION: A hydrogen generator according to an embodiment includes a charged particle generation part, a gas dissociation part, and a hydrogen recovery system. The charged particle generation part generates charged particles and hydrogen from a hydrogen compound gas by electric discharge. The gas dissociation part further generates hydrogen by colliding the charged particles accelerated in an electric field with the remaining hydrogen compound gas or particles including hydrogen atoms. The hydrogen recovery system recovers the hydrogen generated by the electric discharge and the hydrogen generated by the collision of the charged particles.

Description

  Embodiments described herein relate generally to a hydrogen generation apparatus and a hydrogen generation method.

  Hydrogen is expected as a clean fuel. For this reason, development of the technique which produces | generates hydrogen efficiently is desired. As a conventional method for generating hydrogen, for example, a method has been proposed in which a compound such as methane containing hydrogen is dissociated by the action of an electric field, and hydrogen generated by the dissociation is taken out by a pump (see, for example, Patent Document 1). .

JP 2004-331407 A

  An object of the present invention is to provide a hydrogen generation apparatus and a hydrogen generation method capable of generating hydrogen safely and efficiently with a simple configuration.

A hydrogen generation apparatus according to an embodiment of the present invention includes a charged particle generation unit, a gas dissociation unit, and a hydrogen recovery system. The charged particle generator generates charged particles and hydrogen from the hydride gas by discharging. The gas dissociation unit further generates hydrogen by causing the charged particles accelerated by an electric field to collide with the remaining hydrogen compound gas or particles containing hydrogen atoms. The hydrogen recovery system recovers the hydrogen generated by the collision of the hydrogen generated by the discharge and the charged particles.
The hydrogen generation method according to the embodiment of the present invention includes a step of generating charged particles and hydrogen from a hydride gas by discharge, and the remaining hydrogen compound gas or hydrogen atoms of the charged particles accelerated by an electric field. A step of further generating hydrogen by colliding with the particles to include, a step of recovering the hydrogen generated by the discharge and the hydrogen generated by the collision of the charged particles.

  According to the hydrogen generator and the hydrogen generation method according to the embodiment of the present invention, hydrogen can be generated safely and efficiently with a simple configuration.

The block diagram of the hydrogen generator which concerns on the 1st Embodiment of this invention. The figure which shows the detailed structural example of the charged particle production | generation part and gas dissociation part which are shown in FIG. The figure which shows the result of the production | generation test of the hydrogen gas using the hydrogen generator shown in FIG. The figure which shows the detailed structural example of the charged particle generation part in the hydrogen generator which concerns on the 2nd Embodiment of this invention.

  A hydrogen generation apparatus and a hydrogen generation method according to embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
(Configuration and function)
FIG. 1 is a configuration diagram of a hydrogen generator according to a first embodiment of the present invention.

The hydrogen generator 1 is an apparatus that recovers hydrogen (H ₂ ) gas dissociated from a hydrogen compound gas such as methane (CH ₄ ) gas containing hydrogen atoms. Here, a case where the hydrogen compound gas is methane gas will be described as an example. However, hydrogen can be generated from any hydride gas capable of generating hydrogen according to the same principle.

  The hydrogen generator 1 includes a gas cylinder 2, a container 3, a charged particle generator 4, a discharge power source 5, a gas dissociator 6, an electric field power source 7, a gas circulation system 8, and a hydrogen recovery system 9.

  The container 3 can be made of any material having necessary rigidity and sealing properties such as stainless steel. A charged particle generation unit 4 and a gas dissociation unit 6 are installed in the container 3. Further, a gas inlet 10, an exhaust outlet 11, a hydrogen outlet 12, a gas circulation outlet 13 and a gas circulation inlet 14 are formed in the container 3.

  One end of a gas injection pipe 15 connected to the gas cylinder 2 for supplying methane gas is inserted into the gas injection port 10 of the container 3. A first valve 16 is attached to the gas injection pipe 15. For this reason, by adjusting the opening degree of the first valve 16, a predetermined flow rate of methane gas can be supplied from the gas cylinder 2 into the container 3.

  One end of the gas injection pipe 15 is connected to the gas cylinder 2 outside the container 3, and the other end is connected to the charged particle generator 4 inside the container 3. Accordingly, the methane gas supplied from the gas cylinder 2 via the gas injection pipe 15 is guided to the charged particle generation unit 4 in the container 3.

  FIG. 2 is a diagram illustrating a detailed configuration example of the charged particle generation unit 4 and the gas dissociation unit 6 illustrated in FIG. 1.

  The charged particle generation unit 4 is configured by providing a discharge electrode 17 along a flow path of methane gas. The flow path of methane gas can be formed by a cylindrical tube 18 made of an insulator such as glass or acrylic. The cylindrical pipe 18 forming the methane gas flow path may be a part of the gas injection pipe 15 connected to the gas cylinder 2 or may be another pipe connected to the gas injection pipe 15.

  The discharge electrode 17 can be composed of, for example, first and second cylindrical electrodes 19A and 19B. The first and second cylindrical electrodes 19A and 19B are both provided in a cylindrical tube 18 that forms a flow path for methane gas. Further, the first and second cylindrical electrodes 19 </ b> A and 19 </ b> B are connected to a discharge power source 5 provided outside the container 3. The discharge power source 5 is a power source that applies a pulse voltage or a direct current (DC) voltage between the first and second cylindrical electrodes 19A and 19B.

  The inner diameter of the first cylindrical electrode 19A installed on the upstream side of the methane gas is smaller than the inner diameter of the second cylindrical electrode 19B installed on the downstream side of the methane gas. Desirably, the first cylindrical electrode 19A installed on the upstream side of the methane gas is a sharp needle-shaped electrode, while the second cylindrical electrode 19B installed on the downstream side of the methane gas has an inner diameter of And a ring-shaped electrode having a size that fits inside the cylindrical tube 18.

  As a specific example, if the inner diameter of the cylindrical tube 18 is about 2 [mm] to 3 [mm], the outer diameter of the first cylindrical electrode 19A installed on the upstream side of the methane gas is about 0.7 [mm]. The inner diameter of the second cylindrical electrode 19B installed on the downstream side of the methane gas can be about 1.5 [mm].

  Then, the inside of the first and second cylindrical electrodes 19A, 19B becomes a flow path of methane gas. The first cylindrical electrode 19A installed on the upstream side of the methane gas preferably has a structure that closes the gap between the first electrode 19A and the cylindrical tube 18 in order to guide all the methane gas to the inside.

  In the illustrated example, the first cylindrical electrode 19A is inserted into a cylindrical holding member 20 having a through hole. The holding member 20 has an outer diameter that fits the inner diameter of the cylindrical tube 18. Therefore, the holding member 20 functions as a plug that closes the gap between the first cylindrical electrode 19 </ b> A and the cylindrical tube 18. It is realistic that the holding member 20 is made of an insulator such as acrylic.

  When a pulse voltage or a DC voltage is applied between the first electrode 19A and the second electrode 19B with the first electrode 19A having such a shape as a cathode and the second electrode 19B as an anode, a local electric field is It is formed between the first and second electrodes 19A and 19B. That is, an electric field is formed so that the electric flux density is locally increased in the vicinity of the needle-like first electrode 19A. Accordingly, it is possible to perform a spark discharge or a depressor corona discharge between the first and second electrodes 19A and 19B with a small electric power. The discharge area A is a conical area extending from the first electrode 19A toward the second electrode 19B.

  On the other hand, the methane gas has a second cylindrical electrode 19B installed on the downstream side of the methane gas after the flow velocity and pressure are once increased inside the first cylindrical electrode 19A installed on the upstream side of the methane gas. Will flow toward.

As a result, charged particles and hydrogen are generated by the action of discharge from the methane gas injected from the tip of the first needle-like electrode 19A installed on the upstream side of the methane gas. Specifically, in the conical discharge region A, methane positive ions (CH ₄ ⁺ ), methane negative ions (CH ₄ ⁻ ) with electrons attached, hydrogen atoms (H), and dissociation of hydrogen atoms from methane. Accompanying hydrocarbons such as methylene (CH ₂ ) are produced. Therefore, the methane gas that has passed through the cylindrical second electrode 19B installed on the downstream side of the methane gas is generated by the combination of hydrogen atoms and charged particles composed of methane positive ions and methane negative ions. Hydrogen molecule (H ₂ ) is included.

  The gas dissociation part 6 is configured by a pair of electrodes having a structure that allows gas to pass in the electric field direction. For example, as shown in the figure, the gas dissociation part 6 can be configured by facing two mesh electrodes 21A and 21B in which metal fibers are knitted into a sheet shape. In addition, two mesh electrodes 21A and 21B having a gap of 80% and a thickness of 1 [mm] using a metal fiber with a wire diameter of 30 [μm] are actually configured to insulate acrylic or glass. The two mesh electrodes 21A and 21B are held by the holding portion 22 formed of a body, and are arranged at an interval of 4 [mm].

  The two mesh electrodes 21 </ b> A and 21 </ b> B are connected to an electric field power source 7 provided outside the container 3. The electric field power supply 7 is a power supply that applies a pulse voltage, a DC voltage, or an alternating current (AC) voltage between the two mesh electrodes 21A and 21B. The electric field E forms an electric field E between the two mesh electrodes 21A and 21B.

  On the other hand, the outlet of the charged particle generator 4 is configured to be between the two mesh electrodes 21A and 21B. Further, since the charged particle generation unit 4 is connected to the gas cylinder 2, the pressure in the discharge region A formed by the charged particle generation unit 4 is higher than the pressure in the region where the electric field E is formed by the gas dissociation unit 6. It has become.

  Therefore, methane gas containing charged particles and hydrogen is injected between the two mesh electrodes 21A and 21B of the gas dissociation unit 6 by pressure from the charged particle generation unit 4. For this reason, the charged particles flowing into the gas dissociation part 6 are accelerated in the normal direction of the mesh electrodes 21A and 21B by the action of the electric field E formed between the mesh electrodes 21A and 21B.

  Then, the accelerated charged particles collide with particles containing hydrogen atoms such as neutral methane gas particles, methane ions, and other hydrocarbon gases remaining between the mesh electrodes 21A and 21B. As a result, hydrogen atoms further dissociate from particles containing hydrogen atoms such as methane gas, methane ions, and hydrocarbon gas. Thereby, hydrogen is also generated in the gas dissociation part 6.

  The generated hydrogen rises and passes through the mesh electrode 21 </ b> A, and is released outside the gas dissociation part 6 in the container 3. Since the specific gravity of hydrogen gas is small, it is effective to set the normal direction of the mesh electrodes 21A and 21B to the vertical direction.

  The gas circulation system 8 is a system that guides residual hydrogen compound gas such as methane gas and hydrocarbon gas released from the gas dissociation unit 6 and residual methane ions to the gas dissociation unit 6 again. The gas circulation system 8 can be configured by providing a gas circulation pump 24 in a gas circulation pipe 23. The inlet and outlet of the gas circulation pipe 23 are inserted into the container 3 through a gas circulation outlet 13 and a gas circulation inlet 14 formed as through holes in the container 3, respectively.

  The flow of the gas containing methane gas and hydrogen gas is in a rising direction. Therefore, the inlet of the gas circulation pipe 23 is disposed above the gas dissociation part 6. On the other hand, the outlet of the gas circulation pipe 23 is disposed below the gas dissociation part 6. As a result, the methane gas, hydrocarbon gas, and residual ions that have passed through the upper mesh electrode 21A are guided to the lower side of the lower mesh electrode 21B by the gas circulation system 8, and again the lower mesh electrode 21B. Can be passed. Therefore, particles containing hydrogen atoms such as residual methane gas, ions, and hydrocarbon gas can be used repeatedly to generate hydrogen gas.

  The hydrogen recovery system 9 can be configured by providing a second valve 26 in the hydrogen recovery pipe 25. The inlet of the hydrogen recovery pipe 25 is connected to the hydrogen outlet 12 formed as a through hole in the container 3. The hydrogen discharge port 12 is disposed at a position where the hydrogen gas generated in the container 3 can be effectively recovered. Therefore, the hydrogen discharge port 12 is provided as an inlet of the hydrogen recovery pipe 25 at least at a position above the inlet of the gas circulation pipe 23. Preferably, the inlet of the hydrogen recovery pipe 25 is arranged at a higher position in the container 3.

  A hydrogen purification system or a hydrogen storage alloy can be connected to the other end side of the hydrogen recovery pipe 25 as necessary. Then, by adjusting the opening degree of the second valve 26, only hydrogen gas generated in the container 3 can be selectively taken out of the container 3. In addition, the amount of hydrogen gas filled in the upper portion of the container 3 can be adjusted so that methane gas, ions, and hydrocarbon gas can selectively flow into the inlet of the gas circulation pipe 23.

  An exhaust pipe 27 is inserted into the exhaust port 11 formed as a through hole in the container 3. A third valve 28 can be provided in the exhaust pipe 27. Then, before injecting methane gas from the gas cylinder 2 into the container 3, the interior of the container 3 can be kept in a vacuum state by opening the third valve 28 and exhausting. Further, after the methane gas is injected, by adjusting the opening degree of the third valve 28, hydrocarbon gas and ions that do not contribute to the generation of hydrogen gas in the container 3 can be discharged out of the container 3. Furthermore, the pressure in the container 3 and the concentration of methane gas can be adjusted to be a pressure and concentration suitable for the generation of hydrogen gas.

  A pressure gauge for measuring the pressure in the container 3 and a concentration meter for measuring the concentration of methane gas or the like are provided, and the first valve 16, You may make it automatically control so that each opening degree of the valve | bulb 26 and the 3rd valve | bulb 28 may become an optimal opening degree.

(Operation and action)
Next, a hydrogen generation method using the hydrogen generator 1 will be described.

  First, the first valve 16 of the gas injection pipe 15 is opened at a predetermined opening. For this reason, methane gas is injected into the container 3 from the gas cylinder 2 through the gas injection pipe 15. The injected methane gas is guided to the charged particle generator 4.

  A pulse voltage or a DC voltage is applied between the first electrode 19 </ b> A and the second electrode 19 </ b> B of the charged particle generator 4 by the discharge power supply 5. For this reason, a conical discharge region A is formed by spark discharge or depressor corona discharge from the needle-shaped first electrode 19A toward the ring-shaped second electrode 19B. As a result, part of the methane gas that passes through the discharge region A becomes methane ions that are charged particles, and the other part of the methane gas dissociates into hydrogen and hydrocarbon gas.

  Subsequently, methane gas containing charged particles and hydrogen flows into the gas dissociation unit 6 on the lower pressure side than the charged particle generation unit 4. In addition, the pressure in the container 3 including the gas dissociation unit 6 outside the charged particle generation unit 4 is generally about atmospheric pressure. On the other hand, the pressure inside the cylindrical tube 18 of the charged particle generation unit 4 is higher than the atmospheric pressure corresponding to the pressure inside the gas cylinder 2 and the opening degree of the first valve 16.

  Therefore, even if air is mixed in the container 3, the air does not flow into the charged particle generation unit 4. That is, by making the pressure in the charged particle generation unit 4 at least higher than the pressure outside the charged particle generation unit 4, the inflow of air into the charged particle generation unit 4 can be suppressed. As a result, combustion of methane gas in the discharge region A can also be suppressed.

  A pulse voltage, a DC voltage, or an AC voltage is applied between the mesh electrodes 21A and 21B of the gas dissociation part 6 by the electric field power source 7. For this reason, an electric field E is formed between the mesh electrodes 21A and 21B. Therefore, the charged particles contained in the methane gas flowing between the mesh electrodes 21A and 21B of the gas dissociation part 6 are accelerated toward one of the mesh electrodes according to the polarity of the charge and the direction of the electric field E.

  The accelerated charged particles collide with methane gas, methane ions, and hydrocarbon gas existing between the mesh electrodes 21A and 21B. As a result, hydrogen gas is further generated by dissociation of methane gas, methane ions, and hydrocarbon gas. Thus, the hydrogen gas generated by the collision of the charged particles between the mesh electrodes 21A and 21B rises together with the hydrogen gas generated in the discharge region A.

  The raised hydrogen gas passes through the upper mesh electrode 21A and further rises in the container 3. Then, the hydrogen gas rising in the container 3 is recovered outside the container 3 through the hydrogen recovery pipe 25 whose opening degree is adjusted by the second valve 26.

  On the other hand, the gas circulation pump 24 is driven, and the residual methane gas, residual methane ions, and residual hydrocarbon gas released from the gas dissociation unit 6 circulate in the container 3 through the gas circulation pipe 23. For this reason, the residual methane gas, the residual methane ion, and the residual hydrocarbon gas are repeatedly guided to the gas dissociation unit 6 and reused for the generation of hydrogen due to the collision of charged particles.

  Further, the third valve 28 is adjusted as necessary, and a gas that does not contribute to the generation of hydrogen gas is discharged from the exhaust pipe 27 to the outside of the container 3.

  That is, the hydrogen generation apparatus 1 as described above generates charged particles and hydrogen from a hydrogen compound gas typified by methane gas by discharge, and particles containing hydrogen compound gas or hydrogen atoms remaining in the charged particles accelerated by an electric field. Further, hydrogen is generated by colliding with.

(effect)
For this reason, according to the hydrogen generator 1, hydrogen can be generated safely and efficiently with a simple configuration. That is, in the hydrogen generator 1, discharge is performed in a hydrogen compound gas such as methane gas. Moreover, the pressure in the discharge region A is higher than the pressure in the container 3. For this reason, there is no inflow of air into the discharge region A, and there is no danger of explosion which becomes a problem in discharge in the air.

  Moreover, the power consumption required for discharge can be reduced by making the 1st electrode 19A needle shape. In particular, in the depressor corona discharge, a current required for the discharge is small. For this reason, electric power can be further reduced.

  Furthermore, in the hydrogen generator 1, hydrocarbon gas containing methane gas can be circulated to the gas dissociation unit 6. For this reason, the particle | grains containing a hydrogen atom can be reused for the production | generation of hydrogen gas. As a result, the generation efficiency of hydrogen gas can be improved. In addition, since a catalyst is not essential in the hydrogen generator 1, it is possible to eliminate the need for a catalyst corrosion countermeasure.

  For this reason, the hydrogen generator 1 can be used for various purposes. For example, the hydrogen generator 1 can be used for applications such as a hydrogen supply stand for an electric vehicle.

  FIG. 3 is a diagram showing the results of a hydrogen gas production test using the hydrogen generator 1 shown in FIG.

  In FIG. 3, the horizontal axis indicates the discharge time [m] in the charged particle generator 4, and the vertical axis indicates the amount of hydrogen gas [ppm] generated. When discharge was started at time 10 [m], the production of hydrogen gas in the amount shown in the plot of FIG. 3 was confirmed. As shown in FIG. 3, it can be confirmed that 1200 [ppm] of hydrogen gas can be generated 20 [m] after the start of discharge.

  The detailed conditions of the hydrogen gas generation test are as follows: the distance between the first electrode 19A and the second electrode 19B for discharging is 2 [mm], the pressure in the container 3 is 1 [atm], and the first electrode The pulse voltage applied between 19A and the second electrode 19B is 3 [kV], the frequency of the pulse voltage is 125 [Hz], the half width of the pulse voltage is 4 [μs], and between the mesh electrodes 21A and 21B Is 4 [kV], and the distance between the mesh electrodes 21A and 21B is 4 [mm].

(Second Embodiment)
FIG. 4 is a diagram illustrating a detailed configuration example of the charged particle generation unit in the hydrogen generation apparatus according to the second embodiment of the present invention.

  The hydrogen generation apparatus 1A in the second embodiment is configured such that the charged particle generation unit 4A generates charged particles and hydrogen by dielectric barrier discharge (silent discharge). Different from the device 1. Other configurations and operations of the hydrogen generator 1A in the second embodiment are substantially the same as those of the hydrogen generator 1 in the first embodiment. For this reason, only the configuration of the charged particle generation unit 4A is illustrated, and the same components are denoted by the same reference numerals and description thereof is omitted.

  Similarly to the charged particle generation unit 4 in the first embodiment, the charged particle generation unit 4A in the second embodiment also includes the discharge electrode 17 along the insulating cylindrical tube 18 that forms the flow path of the methane gas. Can be configured. However, an insulator is provided between the first electrode 19A and the second electrode 19B constituting the discharge electrode 17. Accordingly, as in the first embodiment, the first electrode 19A disposed on the upstream side of the methane gas has a needle shape, while the second electrode 19B disposed on the downstream side of the methane gas has a ring shape. The rational discharge electrode 17 can be configured by disposing the second electrode 19B outside the cylindrical tube 18 formed of an insulator.

  As a specific example, if the inner diameter of the cylindrical tube 18 is about 2 [mm] to 3 [mm], the outer diameter of the needle-shaped first electrode 19A is set to about 0.7 [mm], and the ring-shaped second electrode 19B. The inner diameter can be set to about 3 [mm].

  Further, a discharge power source 5 for applying a high-frequency voltage is connected to the first and second electrodes 19A and 19B constituting the charged particle generation unit 4A. When a high-frequency voltage is applied between the first electrode 19A and the second electrode 19B, an insulator is present between the first electrode 19A and the second electrode 19B, so that dielectric barrier discharge Happens. For this reason, charged particles are generated as plasma from methane gas passing through the discharge region A. As a result, as in the first embodiment, from the charged particle generation unit 4A, particles containing hydrogen atoms, methane positive ions, methane negative ions, methane, and other hydrocarbons move toward the gas dissociation unit 6. Erupted.

  According to the hydrogen generator 1A in the second embodiment as described above, the same effects as those of the hydrogen generator 1 in the first embodiment can be obtained. Further, since the current required for the dielectric barrier discharge is small, the power consumption can be reduced.

(Other embodiments)
Although specific embodiments have been described above, the described embodiments are merely examples, and do not limit the scope of the invention. The novel methods and apparatus described herein can be implemented in a variety of other ways. Various omissions, substitutions, and changes can be made in the method and apparatus described herein without departing from the spirit of the invention. The appended claims and their equivalents include such various forms and modifications as are encompassed by the scope and spirit of the invention.

DESCRIPTION OF SYMBOLS 1, 1A Hydrogen generator 2 Gas cylinder 3 Container 4, 4A Charged particle generation part 5 Discharge power supply 6 Gas dissociation part 7 Electric field power supply 8 Gas circulation system 9 Hydrogen recovery system 10 Gas injection port 11 Exhaust port 12 Hydrogen discharge port 13 Gas Circulation outlet 14 Gas circulation inlet 15 Gas injection pipe 16 First valve 17 Discharge electrode 18 Cylindrical pipe 19A First electrode 19B Second electrode 20 Holding member 21A, 21B Mesh electrode 22 Holding part 23 Gas Circulation pipe 24 Gas circulation pump 25 Hydrogen recovery pipe 26 Second valve 27 Exhaust pipe 28 Third valve A Discharge region

Claims (7)

A charged particle generator that generates charged particles and hydrogen from a hydride gas by discharge;
A gas dissociation part for further generating hydrogen by colliding the charged particles accelerated by an electric field with the remaining hydrogen compound gas or particles containing hydrogen atoms;
A hydrogen recovery system for recovering the hydrogen generated by the collision of the charged particles and the hydrogen generated by the discharge;
A hydrogen generator comprising:   The hydrogen generation apparatus according to claim 1, wherein a pressure in a discharge region formed by the charged particle generation unit is higher than a pressure in a region in which the electric field is formed by the gas dissociation unit.   The hydrogen generation apparatus according to claim 1, further comprising a gas circulation system that guides the remaining hydrogen compound gas released from the gas dissociation unit to the gas dissociation unit again.   The hydrogen generation apparatus according to claim 1, wherein the charged particle generation unit is configured to form a conical discharge region with a needle-shaped electrode and a ring-shaped electrode.   5. The hydrogen generation device according to claim 1, wherein the charged particle generation unit is configured to generate the charged particles and the hydrogen by dielectric barrier discharge. 6.   5. The hydrogen generation apparatus according to claim 1, wherein the charged particle generation unit is configured to generate the charged particles and the hydrogen by spark discharge or brushed corona discharge. 6. Generating charged particles and hydrogen from hydride gas by discharge;
Further generating hydrogen by causing the charged particles accelerated by an electric field to collide with the remaining hydrogen compound gas or particles containing hydrogen atoms;
Recovering the hydrogen generated by the discharge and the hydrogen generated by the collision of the charged particles;
A method for producing hydrogen.

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